Study: Traffic Noise Could Be Making Us Fat

WASHINGTON – Road, rail and air traffic noises may be contributing to the world’s widening waistlines.

That’s according to a new Swedish study published this week in the Occupational and Environmental Medicine journal.

The researchers looked at the body mass index, waist circumference and waist–hip ratio of 5,075 Swedish men and women, primarily from suburban and semi-rural areas of Stockholm County.

A detailed questionnaire and medical examination provided information on the obesity markers.

They found that every additional 5 decibels of noise correlated with a .21-centimeter increase in waist size.

“Central obesity,” or belly fat, among those exposed to road traffic noise at 45 decibels or more was increased as compared to those exposed below that level, and similar results were seen for waist-hip ratio.

The study concludes that traffic noise exposure can increase the risk of belly fat and that combined exposure to different sources of traffic noise may lead to a particularly high risk.

Researchers note that noise can be a stress factor, which could induce cortisol production, among other stress reactions.

“Elevated levels of cortisol can lead to storage of fat in visceral depots, contributing to central rather than generalised obesity. This may explain why the effects of noise were mainly seen for markers of central obesity, such as waist circumference and waist–hip ratio, rather than for generalised obesity, measured by BMI.”